When glass sheets are heated for forming and annealing, the glass sheet peripheral edge portions have oppositely facing surfaces and an edge surface that affect cooling and resultant tensile and compressive stresses after the annealing is completed. To meet certain manufacturing specifications for formed glass sheets that are annealed, these tensile and compressive stresses must be in a controlled range which can be difficult to achieve because of increased cooling that takes place at the edge portions of the glass sheet as opposed to the central regions where there are effectively only two oppositely facing surfaces from which the glass is cooled.
See U.S. Pat. No. 5,385,786 Shetterly et al.; U.S. Pat. No. 5,536,581 Shetterly et al.; U.S. Pat. No. 5,679,124 Schnabel, Jr. et al.; U.S. Pat. No. 5,865,866 Schnabel, Jr. et al.; U.S. Pat. No. 6,015,619 Schnabel, Jr. et al.; U.S. Pat. No. 6,543,255 Bennett et al.; and U.S. Pat. No. 6,578,383 Bennett et al., the entire disclosures of which are hereby incorporated by reference.